This invention relates generally to mold box assemblies and more particularly to such assemblies which are used to form molded products such as concrete products and which are assembled from a plurality of parts including partition plates which define boundaries of adjacent molded products.
Machines for forming concrete products such as blocks, bricks and pavers, typically utilize a rectangular mold box assembly in which concrete is compressed to form the product. One such machine is described in U.S. Pat. No. 5,059,110 to Allison et al. for APPARATUS FOR FORMING CONCRETE BLOCKS HAVING PLURAL SEPARATELY DRIVEN VIBRATOR SETS. A typical mold box assembly includes a pair of opposed substantially parallel upright end plates and a pair of opposed substantially parallel upright mounting brackets positioned at opposite ends of the end plates which together with the end plates, form a substantially rectangular mold box.
The mold box assembly is put together prior to mounting the same on the machine. In the course of creating the mold box assembly various liners, partition plates, and cores are installed in the interior of the box depending on the type of concrete product which is to be molded therein. Typically, a plurality of substantially identical blocks, bricks or pavers are formed each time the box is filled with wet concrete. When the box is assembled it is mounted on the machine via bolts secured through holes in the mounting brackets on either end of the mold box assembly. The top and bottom of the mold box assembly are open so that a steel pallet which is supported on the machine can be urged against the bottom of the box while concrete is dropped into the top of the box. Thereafter, a head plunger mounted on a vertically moveable portion of the machine lowers into the top of the mold box, thereby compressing the concrete therein and forming the molded products. The molded products are stripped out of the box through the bottom side while continuing to be supported by the pallet.
The end plates in a typical prior art mold box assembly include bores spaced at intervals equivalent to the width of the block, paver, or other product to be formed in the mold box assembly. A slot is formed along the length of each end plate so that the slots in each end plate are facing one another with the bores being formed between the slot and the outer side of each end plate.
The usual mold box assembly forms a plurality of substantially identical concrete products in cavities defined by partition plates which extend between the end plates. Each partition plate includes a tab on opposing ends thereof to which a clevis having a bolt extending from one end thereof is pinned. Each tab and clevis are received in an end plate slot with the bolt extending through one of the bores in the end plate. Thereafter a washer and nut is used to secure the partition plate on each side of the end plate. End liners are then bolted to the inner walls of each end plate between adjacent partition plates and the mold box assembly is mounted on a block forming machine.
In operation, a steel pallet is urged against the lower side of the mold box assembly and wet concrete is poured into the top of the assembly. The mold box assembly can be vibrated during filling and during compaction, when shoes mounted on the machine are urged into the top of the mold box assembly to compress the wet concrete. Sometimes, especially when forming products which require a high degree of compaction, the end plates bow outwardly when the shoes compress the concrete product.
After the product is compressed, the pallet and shoes move downwardly thereby stripping the formed product from the lower side of the mold assembly. The molded product supported by the pallet is cured to form the finished product.
An improved mold box is disclosed in applicant's U.S. patent application Ser. No. 08/373,936, now U.S. Pat. No. 5,542,837 which comprises first and second end plates which are substantially parallel with one another. At least one partition plate extends from one end plate to the other and includes first and second opposing ends which substantially abut the inner sides of the end plates. A slot formed on the inner side of the first end plate extends substantially along the length thereof. The partition plate includes a tab extending from one end thereof which is received in the slot. Locking means extends laterally from the tab. One side plate or liner is mounted on the first end plate over the slot adjacent one side of the partition plate and another side plate or liner is mounted on the first end plate over the slot adjacent the other side of the partition plate. In one aspect, the partition plate is slidable along the slot when the tab and locking means are received in the slot and is constrained from such movement by the first and second plates. In another aspect, the locking means bears against each of the pair of side plates or liners.
The above improved box is intended to allow a user to form molded blocks having a selected width which conforms to the width of the end plates selected. A noted disadvantage with this system is that the individual block widths desired do not exactly fit within the standard mold box used. Thus, specially machined partition plates of a certain thickness are used for each arrangement of partition and end plates. This process is both expensive and time-consuming in that the last partition plate used in the mold must be custom machined to the proper tolerances.
Accordingly, it would be desirable to have an adjustable adapter which can be used in a variety of partition plate arrangements within a standard mold box.